Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations provided, the description carries the full burden. It goes beyond a simple 'returns a map' by explaining the geographic representation of meaning, what the return includes (labels, centroids, counts), and the special VIA quarter with its own MCP endpoints. This gives the agent a clear behavioral model of the data returned, even though it does not discuss side effects, rate limits, or auth—likely irrelevant for a browse operation.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is a single, well-organized paragraph with a clear flow: tag, definition, return values, special case, and use cases. Each sentence adds value, though some conceptual explanation (e.g., 'Geography = meaning') is slightly verbose but necessary for understanding the output. It is appropriately sized for the tool's complexity.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given the lack of an output schema and annotations, the description is remarkably complete. It explains the conceptual model, enumerates all return components (regions, centroids, counts, VIA quarter), and provides concrete use cases. It also links to related tools, helping an agent understand how this fits into the broader tool ecosystem. No significant gaps.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The tool has 0 parameters, so the baseline is 4. The description compensates by clarifying what the output represents and how to interpret it, which is the main semantic need for a parameterless tool. No parameter documentation is needed.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description specifies a clear resource ('Map of the RRG 3D world') and what it returns: every region with label, centroid coordinates, and product count, plus the VIA quarter. It also distinguishes this from sibling tools by explaining the map is the spatial projection of the product embedding space, and mentions search_products and get_drop_details as places where matching world positions appear, showing deliberate differentiation.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description explicitly states when to use it: 'Use this to orient spatial queries (...) to describe where a listing sits in the catalogue, or to direct a human to a region of the world'. It also implies that for individual listing positions, one should look at search_products or get_drop_details, providing context for alternatives, though without explicit exclusions or a direct 'do not use for' statement.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.